The major cause of male infertility is failure to produce
enough healthy sperm. It could be a low sperm count (oligospermia) or a complete absence
of living sperm in the semen (azoospermia). The presence in the semen of large numbers of
abnormally shaped sperm, such as the two- headed one, may reduce a man's fertility.

So, the first thing a infertility specialist do is to
perform a semen analysis. Here, semen is examined as soon as possible for the number,
shape, and degree of motility of the sperm. A postcoital semen test may also be performed.
The semen is analyzed for

Concentration of sperm

Sperm quality

The threshold value for a "normal" sperm/semen is
shown below.

"Normal"
Sperm Formation

Criterion

Value

Volume

1.5-5.0 ml

Density

>20 million sperm/ml

Motility

>30% motile

Normal forms

> 60%

The total sperm count and sperm quality of the general male
population has been deteriorating over the last few decades.

Total Sperm
Supplied by Men Had been Decreasing Over Time

Year

Average Sperm Count

Amount Of Semen

Total Sperm in Ejaculate

1940

113 million/ml

3.4 ml

384.2 million

1990

66 million/ml

2.75 ml

181.5 million

Men are now supplying less than half of the number of sperm
per ejaculate compared to 1940 levels.

Functional Tests to Evaluate Sperm

There are several functional tests to evaluate sperm.

The
post-coital test measures the ability
of the sperm to penetrate the cervical mucus after intercourse.

This is a "test tube version of the post coital
test." Scientists discovered that human sperm, under appropriate conditions, can
penetrate hamster eggs. It was established that fertile males exhibit a range of
penetration of ten to one hundred percent, and that penetration less than ten percent is
indicative of infertility The hamster-egg penetration test is a more reliable indicator of
fertility. It accurately predicts fertility in sixty-six percent of the cases, as compared
to semen analysis that is accurate only thirty percent of time.

Detection Of Antisperm Antibodies

Another important criteria for suitability of fertilization
is the absence of antisperm antibodies in the sperm. If these antibodies are present in
the sperm, they will attack the tail of the sperm, thereby impeding the sperm's ability to
move and penetrate the cervical mucus. (Women also produces the antisperm antibodies. But
the antisperm antibodies produced by women are typically directed against the head of the
sperm.) The presence of antisperm antibodies in semen analysis is usually a sign of past
or current infection in the male reproductive tract.